After decades of debate, disputes over the mathematical rules governing reality remain unresolved

By Tom Siegfried, 10:58 AM November 4, 2010

Schrödinger’s cat was born 75 years ago. Its date of death remains uncertain. Science’s most famous feline remains perpetually both alive and dead, a mythological zombie symbolizing an enduring enigma at the heart of modern physics.

It’s an imaginary cat, of course, invented by Austrian physicist Erwin Schrödinger in 1935 to emphasize the weirdness of quantum mechanics, the mathematical constitution governing the microworld. An experiment could be devised, Schrödinger showed, to put a cat i...